1. Field of the Invention
The present invention relates to an ink jet head and an ink jet printer.
2. Description of the Related Art
An ink jet printer jetting ink on a recording medium such as a sheet, a plastic thin plate or the like to record a predetermined image has been proposed and been in practical use. The ink jet printer comprises an ink jet head having a nozzle (ink jetting opening), the ink jet printer jets ink from the nozzle toward a recording medium while moving the ink jet head in a predetermined direction to record a predetermined image on the recording medium.
For example, Japanese Patent Laid-open Application No. 2002-46256 discloses such ink jet head.
FIG. 8 is an exploded perspective view for explaining a structure of a portion near a nozzle of an ink jet head according to an earlier technique developed by the applicant of the present invention. As shown in FIG. 8, the portion in the vicinity of the nozzle comprises a frame 110, a nozzle chip 120, a flexible wiring substrate 130 and the like.
The frame 110 is fixed in a state properly positioned to have a predetermined positioning relation to a carriage which is not shown in the figure, and moves together with the carriage in a predetermined direction. The frame 110 is fixed in a state positioned to the carriage so that displacement of an ink jetting position can be prevented. Further, in the frame 110, an opening 111 for fixing the nozzle chip 120 is formed.
The nozzle chip 120 is a thin plate shape member as shown in FIG. 8, and comprises a nozzle at a front end portion 121 with openings for jetting ink. The portion near the front end portion 121 of the nozzle chip 120 is inserted to the opening 111 of the frame 110 to be fixed to the frame 110.
To prevent displacement of the ink jetting position and to form a high quality image, it is required to fix the nozzle chip 120 in a state properly positioned to have a predetermined positional relation to the frame 110.
In the earlier technique, the following method is adopted to carry out a positioning of the nozzle chip 120. The inner shape of the opening 111 of the frame 110 is formed slightly larger than the outer shape of the front end portion 121, and protrusions 113 are provided at short sides of the inner shape 112 of the opening 111 of the frame 110. The positioning is carried out based on only one of the protrusions 113 and one of the long sides of the inner shape 114. A long side sulfate 122 of the front end portion 121 of the nozzle chip 120 is abutted on one of the long sides of the inner shape 114 of the opening 111 in the frame 110 in a state pressing to the long side of the inner shape 114 and is adhered to be fixed.
However, when the above-mentioned positioning is adopted, the positioning accuracy is relatively low because the positioning of the nozzle chip 120 is carried out by adjusting the position of the nozzle chip 120 based on only one of the protrusions 113 and one of the long sides of the inner shape 114.
Generally, the frame 110 is made of metal material such as aluminum or the like by die-casting. However, in the above-described positioning in the earlier technique, it is required to form the protrusions 113 on the short sides of the inner shape 112 of the opening 111 in the frame 110 by cutting process. Moreover, fine adjustment is required by performing cutting process in a wide area of the long sides of the inner shape 114. This results in requiring a lot of time and large costs for cutting process.